Arc lamp



May 9, 1933.

0. CONRADTY ARC LAMP Filed Nov. 18, 1929 Inventor;

Patented May 9, 1933 PATENT @FFICE OTTMAB CONRADTY, OF I IUBEMBERG,GEBMANY ABC LAMP Application filed November 18, 1929, Serial No.408,037, and. in Germany November 24, 1928.

My invention relates to improvements in are lamps, and more particularlyin the economizing device provided for heating the crater of the carbonsand for suitably reflecting the light rays. Economizing devices of thischaracter have also been provided in flame arc lamps having an enclosedare.

In constructions now in use the luminous effect of flame arc lampshaving an enclosed are for excluding the air depends on the constructionof the economizing device surrounding the upper carbon downwardly nearlyto the lower luminous cone. Ordinarily economizing devices for flame arclamps are constructed so that the upper part is provided by a member ofchamotte, which member of chamotte has been used ever since the firstconstruction of arc lamps, while below the said chamotte member a metalplate was provided for properly heating the crater of the arc.Economizing devices of this type and the combination of chamotte andiron members are objectionable for the reason that the upper member ofchamotte which has a low conductivity for heat is heated so far that itacts as a mufiie furnace,

and that therefore the metal plate provided below the sameis'superheated to such an extent that the upper carbon is subject todestruction and breaking, and that other drawbacks prevail. For thisreason tne economizing member comprising an iron plate has beenconstructed so that the excessive heating was prevented, for whichpurpose a lower iron plate has been provided which was hori zontal orwhich was even conical and bent outwardly. However, this construction isobjectionable because thereby correct reflection and concentration ofthe radiation is impossible, so that much light is wasted by throwingthe light rays in lateral or upward direction.

.rect shape of the device suitable for reflection to plane or conicalform. With this object in view my invention consists in omitting thechamotte member of the device and providing in-lieu thereof a metalmember having a high surface cooling and con structed for this purposein the form of ribs or laminations, the ribs or other cooling membersexcept the lowermost member being in heat transmitting contact withother parts of the lamps, and the lowermost ring or lamination beinginsulated from the other members and having he function of heating thecra er. Thereby the drawbacks of the chamotte economizing member areobviated, and more particularly the property of the said economizingdevice acting as a mufile furnace and having excessive heating effect.The economizing device composed of ribs or laminations likewise has theproperty of heating the carbon to a certain extent. But it has nosuperlieating effect on the lowermost metal plate or lamination, becausethere is a comparatively high surface cooling by reason of the largesurface of the device, and the device is in heat transmitting Contactwith the other parts of the lamp and the outer sheet metal jacketenclosing the lamp. Since the metal has a high conductivity for heat theparts are cooled to a certain extent by their contact with the metalparts of the lamp. The lowermost lamination or the lowermost ring of thesaid economizing device constructed in the form of ribs or laminationsis used for heating the crater, and therefore its temperature should behigher than that of the upper rings, for which purpose it is separatedby insulating material from the other rings or laminations. 1 have foundthat in this construction in which instead of the chamotte member acooling member of metal is provided heating is not such that it isnecessary to depart from the preferred or reflector form of theeconomizing device. Therefore a good heating of the crater is combinedwith the reflector action.

In order that my invention be more clearly understood two examplesembodying the same have been shown in the accompanying drawing in whichthe same letters of reference have been used in all the views toindicate corresponding parts.

Fig. 1 is an elevation partly in section showing a part of an arc lampand the economizing device mounted thereon,

Fig. 2 is a sectional plan view taken on the line 22 of Fig. 1,

Fig. 3 is an elevation partly in section showing a modification, and

Fig. 4 is a sectional plan view taken on the line 1-4 of Fig. 3.

In Figs. 1 and 2 the reference character a indicates the upper carbonelectrode which is mounted within a guide ring I). The economizingdevice 0 consists of a set of superposed transverse annular laminationswhich are connected with one another by metal rods d and screws. Thesaid metal rods are in heat transmitting connection with the gearing andthe outer sheet metal jacket of the are lam the rods (1 being extended uwardly and xed to the bottom plate h of t e said jacket by nuts 2', 2'.In Fig. 1 the individual laminations have received the characters 0 c, 0c 0 The lowermost lamination 0 is not in heat transmitting contact withthe other laminations, and it is insulated therefrom by means of aninsulating ring 6. The shape of the economizing device is such that themost effective reflection is obtained.

In themodification shown in Figs. 3 and 4 the economizing deviceconsists of sheet metal members in the form of radial ribs 0 mounted onan annular disk f connected with an annular disk 9 by bolts (P. The disk9 is connected with the disk 0 by an insulating rin e. To the to s ofthe ribs 0 a metal plate k is welded whic is fixed to the bottom plate hof the jacket of the lamp by screws i thus transmitting the heat fromthe ribs to the jacket.

I wish it to be understood that the constructions of the economizingdevice shown in the figures are merely examples, and that other forms mabe used, such for example as corrugated sfieet metal lates. Further, Iwish it to be understood t at I do not limit myself to are lamps withenclosed arc, and that the improved economizing device may be used inarc lamps of any type.

I claim:

1. In an enclosed-flame arc lamp for continuous lighting, including aflame-enclosing frame, and carbons therein, a carboneconomizer forpreventing waste of carbon and light rays by controlling the size, shapeand seatin of the flame and focusing the light rays from the uppercarbon below the lamp, comprising a member attached in heat transferringrelation to the upper carbon near one end of the upper carbon and havingaheat-radiating face configured for deflecting radiant heat back intothe carbon crater to maintain the size, shape and seating of the flameconstant and simultaneously In said drawreflecting and focusing thelight rays below the lamp, a. plurality of heat radiating members, saidheat radiating members being connected together in heat transferringrelation to the carbon by means which connect them in heat transferringrelation to said fiame-enclosing frame and being heatinsulated from saidfirst member.

2. In an enclosed-flame arc lamp for continuous lighting, including aflame-enclosing frame, and carbons therein, a carbon-economizer forpreventing waste of carbon and light rays by controlling the size, shapeand seating of the flame and focusing the light rays from the uppercarbon below the lamp, comprising a downwardly opening hemlsphericalmetal plate attached in heat transferring relation to the upper carbonnear the crater end thereof, a similar plate attached in heattransferring relation to said carbon above said first plate andconcentric therewith, a heat insulating member disposed between the twoplates, and a plurality of conical, downwardly opening disks supportedon said second plate transversely of the carbon and heat connected tosaid carbon, said disks constituting laminations of the economizer, thelaminations being connected to the enclosing frame by heat conductingmembers.

3. In an enclosed-flame arc lamp for continuous lighting, including aflame-enclosing frame, and carbons therein, a carbon-economizer forreventin waste of carbon and light rays or controIling the size, shapeand seating of the flame and focusing the light rays from the uppercarbon below the lamp, comprising a downwardly opening hemisphericalmetal plate attached in heat transferring relation to the upper carbonnear the crater end thereof, a similar plate attached in heattransferring relation to said carbon above said first plate andconcentric therewith, a heat insulating member disposed between the twoplates, a downwardly opening conical member supported on said secondplate, a plurality of heat radiating metal ribs arranged radially ofsaid carbon on said conical member, said radial ribs being heatconnected at their inner ends to said carbon and at their tops to saidenclosing frame.

OTTMAR CONRADTY.

